How to make edges of adjacent objects be visible?
Your question is very imprecise, but if you want to see the grooves on the hull you could do it this way:


Join all your objects into one, merge the vertices by distance.
Select the edges that are supposed to become grooves.
Bevel them.
Give some correction in order to have nice grooves (my version needs to be re-worked in order to have a proper topology because it will mess up once you'll give it a Subdivision Surface modifier.
Extrude.